In our practice, when it comes to treating facial and muscle pain and TMJ, we are often queried about the decision-making process behind the use of dual flat plane appliances versus a single full coverage mandibular appliance. Our approach is informed both by our clinical experience in private practice and by the latest insights from the UCLA Orofacial Pain and Dental Sleep Medicine residency, where we contribute as clinical supervisors.

The decision largely hinges on the patient’s dental history and current condition. When no appliance is in place, we assess the wear patterns on the canines and incisors. Factors like occlusal dysesthesia, the patient’s medication—particularly the use of SSRIs like Prozac, Lexapro, Paxil, Zoloft—and signs of bruxism guide us towards recommending dual flat plane appliances. These appliances are more durable against the wear inflicted by natural teeth or porcelain crowns during habitual nocturnal grinding.

Should a patient already have an appliance, visible signs of deterioration such as holes, cracks, or significant wear strongly indicate the need for the more robust dual flat plane solution. These appliances are particularly beneficial for younger patients post-orthodontics, as they double as retainers, thus negating the need for additional orthodontic retainers.

When choosing between an upper or lower single appliance, we consider comfort and functionality. Although studies suggest similar efficacy between the two, we find the lower appliance to be less intrusive, preserving tongue and airway space, and thus more comfortable for the patient. However, the state of the opposing teeth is a critical factor—if the upper teeth are unopposed, an upper appliance is preferable to prevent supraeruption.

For patients presenting with a pronounced click upon opening, indicative of an anteriorly displaced temporomandibular disc, we employ a diagnostic technique using tongue blades. This helps us determine the correct vertical height for the dual flat plane appliances, which can eliminate the clicking sound when properly fabricated. These appliances are worn only at night and are not intended to alter the bite but can potentially resolve clicking if treatment commences soon after the onset.